We couldn’t create a new partition Error 0x9cfc7550 during Windows Setup

If you’re encountering We couldn’t create a new partition, Error 0x9cfc7550 error message on your Windows computer while installing Windows 11/10, then the solution we will present in this post is intended to help you remediate this issue.

This error can occur for a variety of reasons, even on perfectly functioning SSDs and HDDs.

We couldn’t create a new partition, Errror 0x9cfc7550

If you encounter this issue during Windows Setup, you can try the recommended solutions below to see if they help resolve the issue.

1. Disconnect additional Hard Drives, USB drives, and Memory cards
2. Create a new partition using DiskPart
3. Set the intended Windows Install partition as primary/active
4. Use USB 2.0 Drive.

Let’s examine the descriptions of the processes involved with each of the listed solutions.

1] Disconnect additional Hard Drives, USB drives and Memory cards

When using multiple hard drives, the first and foremost thing to do is disconnect all hard drives except the primary hard drive where you install Windows. Once you disconnect all your other hard drive(s), try to install Windows again and see if you can proceed with the installation without encountering the error.

Also, other than the actual Windows 10 bootable USB drive, if you have any other USB drives and memory cards connected to your system, then on rare occasions, Windows might confuse these drives for regular hard drives. Disconnect those additional USB drives or memory cards and try installing Windows again.

2] Create a new partition using DiskPart

This solution will delete all files on your selected hard drive. Use it on a new computer that doesn’t have any files on it, or only if you have a backup available.

To run DiskPart, do the following:

• Start Windows Setup using bootable USB or DVD.
• If you get the error message close the setup and click the Repair button.
• Choose Advanced tools and then select Command Prompt.
• When Command Prompt opens, enter the following command:

start diskpart

• Now enter the following command:

 list disk

You should see the list of all hard drives connected to your computer.

• Find the number that represents your hard drive and enter the command below and be sure to replace 0 with a number that matches your hard drive.

 select disk 0

• Next, input the following lines and press Enter after each line:

disk 0 clean

disk 0 create partition primary

disk 0 active

disk 0 format fs=ntfs quick

disk 0 assign

After running the commands, type exit and hit Enter to close Command Prompt.

Start the installation process again and see if it completes successfully. If not, try the next solution.

3] Set the intended Windows Install partition as primary/active

You might encounter this error if the partition you are trying to install Windows 10 is not active. To make a partition active, you need to have access to the command prompt.

Do the following:

• Start DiskPart as shown above.
• Next, type the command below and hit Enter

 list disk

You should see the list of available hard drives.

• Locate your hard drive and enter the command below and be sure to replace 0 with a number that represents your hard drive.

 select disk 0

• Next, type the command below and hit Enter

 list partition

The list of available partitions will appear.

• Now, locate the partition on which you want to install Windows 10 and type the command below and hit Enter. Replace 1 with a number that matches your partition.

select partition 1

• Lastly, type the command below and hit Enter to set the partition as primary/active.

Active

Type exit and press Enter to exit the Command Prompt.

Start the installation process again and check if the problem is resolved. Otherwise, continue with the next solution.

Read: Windows Setup couldn’t create a new partition or locate an existing one

4] Use USB 2.0 Drive

If you are using a USB 3.0 bootable drive to install Windows, it may also be the reason why Windows is displaying this specific error. To solve it you can try using a USB 2.0 drive.

Hope this helps!

How to create a new partition in Windows Installer?

To create a new partition in the Windows installer, boot from the installation media, then select “Custom: Install Windows only (advanced).” Choose the unallocated space or existing partition you wish to modify, click “New,” specify the partition size, and click “Apply.” Follow the prompts to format and create the partition before proceeding with installation.

How to install Windows 11 on GPT partition?

To install Windows 11/10 on a GPT partition, boot your computer from the Windows installation media. During setup, select “Custom: Install Windows only,” then choose the GPT partition for installation. Ensure your system is in UEFI mode, as GPT requires UEFI instead of legacy BIOS for proper installation and operation.